著者

友成 才

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.69, no.7, pp.267-273, 1974-07-05 (Released:2008-08-07)

参考文献数

6

被引用文献数

1

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In the central part of Chugoku Province, several types of granitic rocks, presumably of Late-Mesozoic are widely distributed. The granitic rocks in the Fuchu District have been hitherto divided into two types, namely, the Hiroshima granitic complex and the Central plutonic complex. Furthermore, the granites belonging to the latter have been divided into three groups; those of the older, the younger, and the unknown ages. Detailed classification and the relationship among these granitic rocks in the Fuchu District have been left unsolved. From the standpoint of petrographical features such as color of potash-feldspar, volume ratio of minerals, chemical composition and occurrence of xenoliths and dyke rocks, granitic rocks of the district can be divided into four types of complex as follows: (1) Mannari type (2) Ashida type (3) Hirotani type (4) Mikawa type The Mannari type granite belongs to the Central plutonic complex, and the other types to the Hiroshima granitic complex according to the current classification. The Ashida and the Mikawa type granites can be divided into those of coarse, medium, and fine grained ones and the Mannari type granite into coarse and fine members. The Mannari type granite has been intruded by the Mikawa and Ashida type. From the field evidences, the Ashida, the Hirotani, and the Mikawa types are considered to be nearly of the same age. Therefore, the Mannari tvpe granite is thought to be the oldest among these four types.